It is a normal practice that after a coating composition is applied to a substrate to form a coating, the coating is then sanded to remove defects to create a desired coating surface. The desired coating surface can have desired smoothness or roughness that may be different from the original coating. Another layer or multiple layers of the same or different coating composition can be applied over the sanded coating surface to finish the substrate.
Different coating compositions can have different intrinsic properties that cause resulted coatings to have different sandability. Sandability of a coating describes how easy to sand the coating and is currently evaluated by specialists in the coating industry by sanding the coating with hand or tools. The specialists then ranking the coating or coatings, based on their judgment, as easy or difficult to sand. The evaluation is mostly subjective and varies from person to person. Since each specialist may use different tools or sanding papers for performing sanding, the evaluation is often not reproducible and inconsistent. Current, there lacks a quantitative measure for evaluating sandability of a coating.
It is therefore in need for a method for measuring sandability of a coating efficiently, quantitatively and reproducibly.